This invention relates to the field of messaging systems. In particular, the invention relates to processing messages for retrieval from a message queuing system.
A typical message queuing system based on the publish/subscribe or point-to-point model allows the retrieval of messages through GET operations or subscriptions. In both cases, the order in which the messages are received is determined by the message queuing system. Generally, a separate GET operation is required for each individual message, so if an application wishes to receive a large number of messages at the same time, it has to cope with the overhead of the large number of requests.
Certain message queuing systems support message grouping, which allows the sending application to define an order on a set of messages, and consequently enables the receiving application to get the messages in the sender defined order. The receiver needs to submit a separate GET request for each message in the group, and cannot override the order.
The capabilities for selectively retrieving messages based on (possibly complex) application specific criteria are limited. The publish/subscribe messaging model allows subscribing applications to choose topics to subscribe to. Topics allow applications to select messages on a high level, which is not appropriate for certain applications.